Electric circuit for polarized compound electromagnet



0. S. FIELD April 22, 194?.

ELECTRIC CIRCUIT FOR POLARIZED COMPOUND ELECTROMAGNET Filed Jan. '7, 1944 Patented Apr. 22, 1947 ELECTRIC CIRCUIT FOR POLARIZED COMPOUND ELECTROMAGNET Oscar S. Field, Rochester, N. Y., assignor to General N. Y.

Railway Signal Company, Rochester,

Application January 7, 1944, Serial No. 517,388

1 Claims. 1

This invention relates in general to improved light signals adapted for use on railways, and has more particular reference to improvements in search light signals of the SC type.

The signal disclosed in the present application is to be considered in the nature of an improvement over the signal of the same general type disclosed in my prior application Ser. No. 361,060, filed October 14, 1940, now Patent No. 2,376,534, dated May 22, 1945, and no claim is intended to be made in this application covering any subject matter common with such prior application.

One of the objects of the resent invention is to provide means for interconnecting the spectacle and the two operating armatures of this type of light signal, so as to provide a simple, economical, rugged, and long'lived device.

Another object of the present invention is to provide means, largely of a structural nature, whereby temporary loss of shunt in a track circult will not cause an improper and undesirable operation of light signals of this type when controlled by a track circuit.

Further objects, purposes and characteristic features of the present invention will appear as the description progresses, reference being made to the accompanying drawings showing, solely by way of example, and in no Way whatsoever in a limiting sense, one form which the invention can assume. In the drawings.

Fig. 1 is a fragmentary, diagrammatic view of the embodiment of this invention.

Fig. 2 is a fragmentary view of a connection constituting part of this invention.

Fig. 3 is a sectional view, on lines 3 3 of Figs. 1 and 2, and viewed in the direction of the arrows.

Fig. 4 is a circuit diagram, showing one application of the improved light signal in accordance with this invention.

Figs. 5 and 6 are respectively fragmentary plan and front elevational views ot a detail of construction.

Fig. '7 is a fragmentary sectional view on line 'l-l of Fig. 8, viewed in the direction of the arrows of a second detail of construction.

Fig. 8 is a fragmentary front elevational view of the second detail of construction.

Referring now to the drawings and first to Fig. 1, there is here shown a portion of a signal in accordance with this invention with only those parts shown that are necessary for a complete understanding of the invention. The signal includes a red-yellow electro magnetic operating member RY and a similar yellow-green operating member YG.

The red-yellow operating member includes core portions 3 and 4, below which is pivoted, as by pivots 5, an armature B and shown in the drawing in its retracted position. In like manner, the yellow-green operating member includes core portions 1 and 8, and an armature 9 having pivots l0, and this armature likewise is shown in its retracted position. As in the above referred to application, the armatures are moved magnetically to their attracted positions when their operating coils (not shown in this figure) are energized, unless otherwise prevented from assuming such positions.

A usual light control spectacle H, carrying colored transparent roundels R, Y and G, respectively colored red, yellow and green is connected at its lower end 52 to a shaft 13, carried on pivots I4. Upon rocking of shaft l3 the spectacle is swung to progressively bring the colored roundels opposite a light source, as represented at l5,.to thereby display either a red, yellow or green aspect.

The shaft [3 carries an off-set crank, having two arms I6 and IT. The crank arm I! is pivoted to the depending stem portion l8 of a T-shaped floating lever, having its head formed by oppositely extended arms [9 and 23, the arm [9 being pivoted to armature 6 and the arm 20 being pivoted to armature 9. These arms are pivoted to their armatures by universal or ball and socket joints one of which joints is shown in detail in Figs. 2 and 3.

The joint connecting arm I9 to armature 6, is constituted by a ball 2| which has a driven fit into a cylindrical hole 22, which hole is symmetrically positioned with respect to a flat sided slot 23 extending inwardly a considerable distance beyond the inner end of the hole. Slot 23 receives the free end of arm I9, which free end is bifurcated to have upper and lower fingers 24 and 25 spaced from each other sufficiently tobe received over the ball 2! with sufficient clearance to permit easy movement of the fingers on the ball. The inner faces of the fingers Z4 and 25 are arcuate in form so as to conform to the contour of the bearing ball 2| with the slight clearance above stated. With the construction as just described, it is clear that the joint between arm i9 and armature 6, constitutes a universal joint and permits free pivoting of the two members with respect to each other, the ball received in the armature bore with a driven fit being fixed with respect to the armature.

In the same manner, arm 20 is pivoted at its outer end to armature 9 by a ball and socket joint including a ball 26 on which is received the forked or bifurcated end of arm 20. The arms 19 and 28 as well as the balls 2! and 2* are made of non-rusting material as brass or bronze while the armatures 6 and 9 are of magnetic and rustable material. Thus, the ball joints are so made as to avoid any sliding of parts that are of rustable material in order to minimize friction. It is contemplated, however, that the arm !9, for example, could be tight on the ball 21 and the ball be loose enough in the armature to both slide and rotate. Also, if desired both the ball and the end of the arm could be loose, respectively, in the armature and on the ball. In each case, it follows that on the movement of either armature, the arms are free to turn and to slide, which action is necessitated not only because of the armatures being constrained to movement in a vertical plane, but also due to the connection to the crank arm l6. Thus, each joint constitutes a sliding universal joint. It should be noted that the end of arm l9 (Figure 2) is sufficiently spaced from the inner end of slot 23 to prevent it striking the end of the slot. The same is true of arm 20.

With the above described construction it appears clear that, upon either of the armatures 8 or 9 assuming attracted position, depending arm i8 of the floating lever is raised to rock shaft l3 and shift the spectacle with respect to the light source l and upon the picking up of the other armature while the first armature is up, the spectacle is moved a further distance. The parts are so proportioned that the spectacle which is biased when the signal is deenergized to display the red indication, is moved sufiiciently to display a yellow indication upon the energization of either operating member, and to shift it a further distance to display a green indica tion upon the contemporaneous energization of the other operating member.

As described above the spectacle is carried by one end of shaft l3 while the other end of the shaft is connected by means of the crank 16 to the operating armatures. This showing is wholly schematic and shows no detail of actual construction.

The connections just referred to in one actual form of construction Will now be described in connection with corresponding figures of the drawings.

As shown in Figs. 5 and 6, the connection between the depending portion 18 of the floating lever and shaft l3 includes a pivot pin 60 held in spaced ears 6! and 52 which are formed on the crank proper. The crank is constituted essentially of a ribbon loop 64 of spring material formed in the shape of an open-ended loop, with the ears carried by one of its ends. The loop 64 has its other end held in a slot 65 in shaft I3 by suitable means as rivets 66 and an adjusting screw Bl. The adjusting screw 6'! passes through the lower arm of loop 84 and is threaded through shaft l3. On this screw is a lock nut 68 for holding the screw in adjusted position. The loop is biased to a wider open position than that shown in the drawing whereby by turning the screw inwardly or outwardly the loop is held more contracted or is allowed to expand to thereby turn shaft l3 and with it the spectacle II. In this manner the initial or deenergized position ofthe spectacle can be accurately adjusted by means of screw 61 and the adjustment dependably maintained by means of lock nut 68.

Referring now to Figs. '7 and 8, there is here shown one actual form of construction for connecting spectacle l l to the operating shaft l3. At the end of the shaft is a flat faced plate ll, which is integral with or fixed to the shaft. Against the face of plate H is a friction plate 12 of fibre or relatively soft metal such as copper or the like, while against the face of the friction plate 12 is a brake plate 13. The plates are fastened together near one edge by a screw 14 which snugly fits its receiving holes in the plates to thereby form a pivot connection. Sleeved on screw 74 between plate 13 and the screw head is a coil spring 15 which operates to press the plates together with a suitable degree of pressure.

Near an opposite edge of the plates is a screw 16 which is snugly received in receiving openings in plates ll and 12 but loosely received in an opening in brake plate 13, as indicated at H. It is clear from this that brake plate 13 can slide with respect to the plates TI and 12 to a limited extent, as defined by screw 16 and its receiving opening in plate 13.

As seen most clearly in Fig. 8, shaft 19 of the spectacle is carried by braking plate 73 by means of a receiving jaw and a spaced receiving jaw 8| carrying clamping screws 82, thereby to securely fix the spectacle to the braking plate.

Upon the spectacle moving to either extreme position, any tendency for the spectacle to rebound and thereby adversely affect the signal indication, is effectively prevented by the absorption of the energy of the moving parts by friction as the braking plate slides on plate 12. Thi frictional movement of the plates takes place in one direction when the spectacle moves to its deenergized position and in the other direction when the spectacle moves to its fully energized or clear position. Thus, the connection of the spectacle to the shaft is by means of frictional break-down connection restrained to a limited amount of relative motion, and all re-bound and vibration is effectively prevented.

It follows, therefore, that the energization of but one operating member changes the signal aspect from red to yellow, and the contemporaneous energization of both operating members produces a green signal indication.

In order that the signal shall not swing from red to green momentarily and then return to yellow, under certain transient conditions and thus produces a flash of the green, means is provided to prevent this confusing and undesirable operation. This means is constituted by a structural interlock or loading arm, whereby armature 9 cannot pick up until after armature 6 is already picked up. This loading structure comprises a rigid arm 28 in the form of a channel fastened to the under part of the front end of armature 9 by a screw and nut 29, constituting in addition to a fastening means an adjustable front stop for the armature and by rivets or pins 30 and 3| constituting usual residual pins, in addition to being fastening means. The rigid arm 28 extends across the gap between the two armatures and bears against the lower face of armature 6 when this armature is in released position. The free end of arm 28 is cut out as shown in Fig. 1 and is of the proper length to prevent any side play of the armatures causing interference with the arm by the front stop 33 and pins 32, 32 In this manner, armature 9 is loaded with the weight of the armature B, in addition to the spectacle and its own weight, and hence through its operating coil be energized, it will not pick up until after armature 6 has picked up.

Armature 6 carries usual residual pins as 32 and an adjustable front stop 33 of the same type as described above in connection with armature 9.

The significance and advantages of this improved form of spectacle operating means, in this search light type of signal can be most readily understood from considering an example of its application in practice.

In Fig. 4 is shown one application of this improved form of signal structure. There is here shown a stretch of single track constituted by track rails 34 separated into usual isolated track sections by insulating joints 35, one complete section B and the adjacent ends of sections A and C, being shown. Section B includes a source of energy 38, an adjustable resistance 31 and a track relay 38, in the usual manner. Sections A and C are, of course, likewise constituted although the drawing fails to so show them. In connection with the entrance end of section B, is a wayside signal of the type and construction as described above. This signal is controlled in the usual manner by traflic conditions in its own block B and the two blocks next in advance and so arranged as to display a red indication when its block is occupied, as in the condition shown in the drawing, as note the vehicle 39. It displays a yellow indication when its block is unoccupied but the block next in advance is occupied, and to display a green indication when its block and the block next in advance are both unoccupied.

The signal shown in Fig. 4 is of the polarized type, the yellow-green operating member YG having an energizing winding 4| so poled with respect to a permanent magnet 42 as to operatively respond only to energy of one polarity which can be characterized as normal or positive polarity. The operating member RY has an energizing winding 43 which is connected to the output side of a rectifier 44 of the full-wave type, connected to both windings as shown in the figure of drawing and as disclosed in detail in the application above referred to.

Accordingly, as so disclosed in this referred to application, energy applied to the signal through wire 45 and of negative or reverse polarity causes operation only of the RY operating member, while energy so applied of normal or positive polarity causes operation of both operating members to respectively change the signal aspect from red to yellow, and from yellow to green.

In the operation of the signal in the situation shown, it may occur in practice that a short train or single vehicle, particularly if light and travelling at high speed on passing out of block B and into block C, may cause the track relay 38 of the vacated block to pick up before the track relay of the newly occupied block C has released. In this case, there is a temporary loss of shunt, and the condition temporarily is the same as if the vehicle had been lifted clear of the track. This condition exists until after the track relay for block C has released, and the signal for block C has responded to this release and its operating member RY has released to thus pole change the current applied to wire 45 through wire 45 from the temporary or transient condition of normal or positive polarity to the proper negative or reverse polarity.

Under the above mentioned transient condition, the two operating members of the signal for block B are energized and both armatures would, if not prevented, pick up and the signal would display a green indication. So soon as the temporary condition ceased to exist, the signal would then swing back to its yellow position. Thus the signal for block B would cause an undesired and unintended flash of the green. The electro-magnet for the RY operating member is made slower to respond to energy than is the YG operating member, and further is slower to pick up than it is to release. This is accomplished in any desired or well-known manner, as by means of a short circuited low' resistance winding or slug i! on the core 48 of the member, in connection with proper adjustment of the applied energy level, air gaps, etc. all as are recognized by those versed in this particular art. Accordingly, while the windings of the two operating members are both energized for a short period of time under the transient condition referred to the RY operating member is slow enough to pick up to bridge over this temporary period and due to the effect of the loading arm 28, the armature of the yellow-green operating member cannot pick up, the RY member armature preventing it from so doing. Thus, the signal for block B, under the stated conditions, responds properly to traffic conditions and moves only from red to yellow positions, and any undesired and unintended flash of the green is wholly prevented.

In Fig. 4 has been shown but one example of the application of this improved structure, there being other applications where it is very desirable, as for instance, in connection with intermittent inductive train control systems. This application is set forth in detail in an application filed of even date herewith in the name of T. J. Judge, Ser. No. 517,389, dated January 7, 1944, and attention is directed to such application for a more complete understanding of this particular application of the signal.

The above rather specific description of one form of this invention is given solely by way of example, and is not intended, in any manner whatsoever, in a limiting sense. It is to be understood that various modifications, adaptations and alterations may be made from time to time, to meet all requirements of practice and expediency without, in any manner, departing from the spirit and scope of this invention, except insofar as it may be limited by the appended claims.

Having described my invention, I now claim:

1. In a light signal of the search light type, a pivoted shaft, a member carried by the shaft, two spaced operating members each including an electro-magnet and an armature movable from a retracted to an attracted position, a rigid floating lever pivoted at each end, respectively to the armatures, a crank on the shaft, a stem connecting the crank to an intermediate point on the lever, and a rigid loading arm fixed to one armature and extending across to bear against the lower face of the other armature when both armatures are in retracted positions.

2. In a light signal of the search light type, a pivoted shaft, member carried by the shaft, two spaced operating members each including an electro-magnet and an armature movable from a retracted to an attracted position, a rigid floating lever pivoted at each end, respectively to the armatures, a crank on the shaft, a stem connecting the crank to an intermediate point on the lever, a rigid loading arm fixed to one armature and extending across to bear against the lower face of the other armature when both armatures are in retracted positions, and means associated 7 with the eloctro-magnet of said other armature for making its armature slower to act than said one armature and also slower to pick up than to release.

3. In a light signal of the search light type, a pivoted shaft, 2. member carried by the shaft, two spaced operating members each including an electro-magnet and an armature movable from a retracted to an attractez. position, a rigid floating lever pivoted at each end, respectively, to the armatures, a crank on the shaft, a stem connect ing the cranl: to an intermediate point on the lever, and a rigid loading arm fixed to the armature of one eleetro-magnet and extending across to bear against the lower face of the armature of the other electro-magnet when both armatures are retracted positions, means associated with said one electro-magnet for making its armature slower to act than is the armature of said other electro-magnet and also slower to pick up than to release, and means associated with said other electro-niagnet ior polarizing it so that its armature responds only t polarity.

i. In a light signal oi the search light type, a shaft, a device on the shaft and biased to a first position and movable to second and third positions, two operating members for the device each including an electro-magnet and an armature, means operatively connecting each armature to the shaft so as to rock the shaft and move the device to its second position with a particular one of said arinatui'es in attracted position and to its third position only when both said armatures are in attracted positions, and a rigid loading arm fixed to the other armature and bearing against the lower face of said particular armature when both of the armatures are in retracted positions.

5. In a light signal of the search light type, in combination, a shaft, a device on the shaft and biased to a first position and movable to second and th'" positions, two operating members for the le ce each including an electro-ma-gnet and an iature one electro-magnet being polarized and the other non-polarized, means operatively connecting each armature to the shaft so as to rock the shaft an move the device to its second positi n with the armature of the nonolarized attracted position and to its th sition onl when both armatures are in attracted positions, circuit means for concurrently applying energy of either polarity to the two electro-magnets, means making the nonpolarized magnet slower to act than the other magnet and also slower to pick up than to release its armature, and a rigid loading arm fixed to the armature of the polarized magnet and bearing against the lower face of the armature of the non-polarized electro-magnet when both armatures are in their retracted positions.

6. In a light signal of the search light type capable of displaying different indications in accordance with the position of a movable element, a polarized electro-magnet and a non-polarized electro-magnet each having an armature movable from a biased position to an attracted position upon the energization of that electro-magnet, said polarized electro-magnet requiring energization by a particular polarity in order to actuate its armature to an attracted position, operating current of a particular (Electra-magnet in means controlled by said armatures for causing said element to assume a first position when both said a-rmatures are in their biased positions, for causing said element to assume a second position when the armature of said non-polarized electromagnet is in an attracted position, and for causing said element to assume a third position when both of said armatnres are in attracted positions, a. mechanical means associated with the armature of said polarized electro-magnet and acting independently of said operating means for preventing the movement of that armature to an attracted position while the armature of said nonpolarised electro-magnet is in its biased postion, and means including a short circuited winding associated with said non-polarized electro-magnet for rendering its armature slow to respond to the energization and deenergization of that electro-magnet.

In a light si nal of the search light type capable displaying different indications in accordance with the position of a movable element, polarized electro-magnet and a non-polarized electro-magnet each having an armature movable from biased position to an attracted position upon the energization of that electro-magnet,

electro-magnet requiring energize.- tion of particular polarity in order to actuate s armature to an attracted position, operating ineans controlled by said armatures in their biased pos'tions for causing said element to assume a f s position, but causing said element to assume second position when the armature of said nonpol rize electro-magnet is in an attracted position and causing said element to assume a third position when both of said armatures are in attracted positions, a, mechanical means separate from said operating means and associated with the armature of said polarized electro-magnet for preventing the movement of that armature to an attr cted position while the armature of the nonized eiectro-magnet is in its biased position, a copper slug associated with said non-polarized electro -magnet for rendering its armature slow to respond to the energization and deenergization of that electro-magnet, and polarized circuit means for times energizing said electro-ma nets in series, said circuit means including 3 rectifier for always energizing said non-polarized electro-magnet in the same direction, whereby a quick reversal of polarity in said circuit does not result in the release of the armature of said nonpolarized electro-magnet, and whereby said polarizod electro-magnet can actuate its armature to an attracted position only when said circuit means is energized with a particular polarity and then only if the armature of said non-polarized electromagnet has been actuated away from its biased position.

OSCAR S. FIELD.

REFERENCES CITED lhe following references are of record in the file of this patent:

UNITED STATES PATENTS Nun: Name Date 2,035,395 Merkel Mar. 24, 1936 210L186 Moore Dec. '7, 1937 2,172,724 Wells et al. Sept. 12, 1939 2,337,651 Douglass Dec. 28, 1943 

